Truing device



Dec. 19, 1933. H. w. HOLMES 'TRUING DEVICE Filed Aug. 14, 1926 35.\ H118 @(56 4 lll 4o 75 62 70 'Ik @4 4' 4 3h92 I. 1 1%- ;9 7? y f :j

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. nr-*"1"* nl un- L 101 50 Ja 1- 9j/nj 1 1* a i l Patented Dec. 19, 1933TRUING' DEVICE Harold W. Holmes, Detroit, Mich., maar, by

mesne assignments, to Cincinnati Grinders `Incorporated, Cincinnati,Ohio, a corporation oi.

Ohio

Application August 14, 1926. Serial No. 129,185

4 claims. (ci. 12s- 11) 'I'his invention relates to grinding machinesand more particularly to devices for useI in conjunction with grindingmachines for truing the surface of abrasive wheels. This application isa l continuation in part of my co-pending application Serial No. 672,844filed November 5, 1923 for Centerless grinder.

It is the object of the present invention to provide a grinding machinearranged with a device l. which is readily accessible for accuratelytruing the surface of the abrasive wheel therein, and particularly suchya device which is arranged for properly shaping the surface of theregulating wheel of a two wheel centerless grinding machine 1| from aposition other than upon the line of contact between the work and theregulating wheel. Another object of the invention is to provide amechanism for dressing or truing the surface oi an abrasive wheel whichis of simple construction 20 and thoroughly practical. Another object isto provide a mechanism of this nature which is eilicient inaction andconveniently adjustable to meet the varying requirements of practicaluse. Other objects will be in part obvious or in part 25 pointed outhereinafter.

The invention accordingly consists in the features of construction,combinationsof elements, and arrangements of parts as will beexempliiled in the structure to be hereinafterdescribed and 340 thescope of the applicationoi which will be indicated in the followingclaims.

In the accompanying drawing in which Iis shown' one of 'the variouspossible embodiments' of this invention, 35 Fig. 1 is a sectional sideelevational view or a portion of a grinding machine embodying theinvention;

Fig. 2 is a front elevational view of a portion of the same; mg. a 1s a.detail pimview if` a poi-non of the same partly in section; and

Fig. 4 is an end, elevational viewy of the parts shown in Fig. 3.

In the drawing the invention is illustrated as embodied in a'two wheelcenterless grinding machine comprising a base having a hollowcylindrical portion adapted to receive a cylindrical column 11 which isslidably mounted therein. A support 12 is mounted on the top of thecolumn 11 to turn about the pivot 13 and may be secured in any desiredposition thereon by bolts 14 en gaging threaded holes in the column andpassing through arcuate slots 15 in the support. A spindle 16 is mountedin suitable bearings li in 55 the support l2 and carries a regulatingwheel 18 of any suitable'material, such as abrasive material, mountedfor rotation therewith. A grinding wheel 20 is mounted upon a spindle(not shown) for rapid rotation in suitable bearings held in the frame ofthe machine. Suitable holding means such as members or plates and 26,for example,are provided for maintaining a work piece 27 in properposition between the grinding Wheel and the regulating wheel and,preferably, these are adjustably mounted upon the column 11. l

A water pan 30 is adjustably mounted upon a flange 31 of the column 11by bolts 32 threaded into the pan and passing through arcuate slots 33in the flange. The water pan 3 0 is provided with a fiat bearing surface34 upon-which a su'pport or male slide 35 is mounted'to turn about apivot 36 having a shoulder 37 resting against the water pan and heldthereagainst by a nut 38 engaging a threaded portion o! the pivot 36.The slide 35 may be adjusted angularly about the pivot pin 36 andsecured in any desired angular position by bolts 40 passing througharcuate slots 41 into threaded holes 42 in the water pan 30. The extentof adjustment of the slide 35 may be indicated by a scale 43 (Figure 2)thereupon.

By means of the bolts 32 operating in the arcuate slots 33 the water pan30 and the complete truing-mechanismwhich is carried thereby areadjusted angularly in position with respect to the axis of theregulating wheel. When the bolts 32 are loosened and the water pan isswung for' adjustment, the truing mechanism swings therewith about theaxis 13 around which the regulating wheel is pivoted and about which thelatter may be adjusted to give the desired angular relation between theaxis of the regulating wheel and the axis of the work, which angularrelation causes the regulating wheel to feed the work along. Preferably,in ordinary operation, the water .pan is adjusted about-the pivot 13 sothat i the surface 34 thereof lies in a plane which is substantiallyparallel to a plane passing through the axis of the regulating wheel.

A slide. 44 having suitable slideways 45 for engagement with similarslideways` 46 upon Vthe male slide 35 is provided with a cylindricalportion 47 passing through a hole 48 in the water pan. The cylindricalportion 47 of the slide is provided with a hole 49 to receive acylindrical slide 50 keyed to move freely therein towards and from theregulating wheel and extending beyondthe cylindrical portion andcarrying a cover cap 51 secured thereto by a pin 52 and overlapping oneend of the cylindrical portion 47. A A dresser 110 55 on the cap 51 by anut 56.

The slide 50 is provided with a threaded hole 60 to receive an adjustingscrew 61. A cover cap 62 is mounted upon the outer end of thecylindrical portion 47 so as to rest against a shoulder 63 upon thescrew 61 and is prevented from turning relative to the part 47 by a keyengaging a slot 65 in the cap 62. A spring 66 surrounds the screw 61 andis adapted to engage an internal shoulder 67 upon the cylindricalportion 47 of the slide 44, the other end of the spring is arranged toengage the inner closed end of the cover cap 62. An adjusting knob 70 isprovided with a slot 71 for engagement with a key 72 in the endvof thescrew 61 and is held thereupon by a nut 73.,

One end of a forming bar 75 is pivoted by a pin 76 in a bracket 77 whichis secured to the male slide 35 by screws 78. The other end of theforming bar 75 (Figure 3) is provided with a bearing 79 adapted toengage the inclined surface 80 of a block or wedge 81 adjustable in abracket 82 which is secured to the male slide 35 by screws 83. Theposition of the block 81 Within the bracket 82 may be adjusted byturning a knob 86 resting against a shoulder 87 and engaging thethreaded portion of a screwv 88 projecting from the block 81. Axialmovement of the knob 86 in either direction is prevented by theprovision of a U-shaped washer 89 engaging a groove 91 in the knob andsecured to the bracket 82 by screws 90 (Figure 4). I

As shown in Figure 1, the cap 62 has on the underside thereof a boss 62ain which is held a downwardly projecting short shaft or spindle 62h.Upon the spindle 62h is a roller 62o which engages with the surfaceofthe forming bar 75. The spring 66 urges the cap 62, and with it themembers 61, 50 and the dressing tool 54, to the left, as Viewed inFigure l, or in a direction away from the surface of the regulatingwheel 18. The action oi the spring 66 holds the roller or follower 62eagainst the surface of the forming bar 75. Thus, when the slide 44 ismoved along the ways 46 of the adjustable plate 35, the roller 62follows along the surface of the forming bar 75 and is constantly heldthereagainst by the spring 66, the spring tending always to draw thedressing tool away from the wheel surface. The shape of the'forming bar75 thus determines the path of movement of the dressing tool across thewheel surface. As shown herein, the operative sui-race of the formingbar 75 is-shown straight and hence the path of travel of the dressingtool follows a straight line. By turning the thumb wheel 86, theleft-hand end of the forming bar, as viewed in Figures 2 and 3, is swungoutwardly in a direction away from the regulating wheel surface, thuschanging the angular position of the forming bar with respect to theregulating `wheel. Thus, by adjusting the position of the.

forming bar 75, the path of movement of the dressing tool is adjustedangularly in a plane approximately at right angles to the plane ofangular adjustment effected by swinging the supporting plate 35.

The slide 44 is provided with a nut 100 integral therewith and adaptedto engage a screw 101 mounted in a bearing 102 (Figure 2) upon the slide35 and provided with a collar 103 adapted to rest against the bearing102. A hand wheel 104 having a handle 105 is mounted upon the screw 101so that its hub 106 rests against the other side of the bearing 102 andthe hand holder 53 carrying a dresser 54 is held in a lug wheel is heldupon the screw 101 by a nut 107. The screw 101 is thus held againstaxial movement and when it is turned by means of the hand wheel 104 theslide 44 is moved along the ways 46 and lengthwise of the angularlyadjustable plate 35the follower 62e bearing against the forming bar 75during this movement.

One end of the regulating wheel 13 is marked off into four equalsegments by lines 108 positioned 90 degrees apart. When the work 27 isproperly positioned between the wheels with its line oi" contact withthe regulating wheel intersecting one of the lines 108, the dresser 54preferably engages the surface of the regulating wheel at theintersection therewith of the next adjacent line 108. When it is desiredto dress the regulating wheel the slide 44 is brought to the properangular relation relative to the axis of the regulating wheel byloosening the bolts 40 and swinging the slide or plate 35 about thepivot 36 until the proper angular relation is indicatedL upon the scale43. When the regulating wheel is inclined or tilted to effect an anglebetween the axis of the work and the axis of the regulating wheel, thisangle should be equal to the "angle between the axis of the work 27 andthe axis of the regulating wheel 18 when the dresser engages theregulating wheel on a line 90 degrees from the line of contact of thework therewith. With the dressing or truing mechanism thus adjusted, thedresser 54 is brought into contact with the surface of the regulatingwheel at the point of intersection o one of the lines 108 by turning theknob 70. The slide 44 is then actuated to move the dresser 54 across theperiphery of the regulating wheel by turning the hand wheel 104 to movethe screw 101 within the nut 100.

With the wheel trued in this manner, the axis of the regulating wheelbeing at an angle to the axis of the grinding wheel and the axis of thework to exert a feeding component on the work, a concave peripheralsurface is formed thereon so that, when the work 27 is properlypositioned between the wheels with its axis parallel to the axis of thegrinding wheel, it will contact with the surface of the regulating wheelalong a straight line. Thus, the regulating wheei is provided with asurface such that it may dependably control the rotation of the work anddependably feed the work axially between the wheels.

)in order to assure that the guiding surface of the forming bar 75 isproperly positioned relative to the axis of the regulating wheel, oneend of the forming bar is mounted'so that it may be adjusted toward oraway from the surface or axis of the regulating wheel as abovedescribed. In practice, it is preferable to true the surface of theregulating wheel so that the distance between its surface and theperipheral surface of the grinding wheel is slightly greater at that endat which the work Venters therebetween. In order` to shape the surfaceof the regulating wheel in this manner the bearing 79 on one end of theforming bar 75 is moved towards or away from the surface of theregulating wheel by turning the knob 86 a desired amount prior to truingthe wheel.

In grinding work which is not to be fed axially through the machine, theaxis of the regulating wheel n not skewed but is positioned parallelwith the axis of the grinding wheel. This may be accomplished by turningthe support 12 about the pivot 13 and securing it in approprif ateposition by the bolts I4 and 15. So also, when it is desired to true theregulating wheel when in this position, the slide V must be adjusted soas to'permit the dresser 54 to traverse the surface `of the regulatingwheel along a line parallel with the axis of the grinding wheel.

While the invention has been illustrated by reference tov a device inwhich the dresser travels along a line positioned 90 degrees from theline of contact between the work and the regulating lWheel, it will bereadily apparent to those skilled vin the art that the dresser maytravel along a line positioned at some other angular distance from theline of contact between the work and the regulating wheel. Y

Having thus described my invention,` what I claim as new and desire tosecure by Letters Patent is:

1. An apparatus for truing the peripheral op` erative surface of theregulating wheel of a centerless grinding machine in which there existsan inclination between the axis of rotation of the regulating wheel andthe path of travel'of the work piece being ground so that the regulatingwheel exerts a feeding component upon the work, including, incombination, a dressing tool, means mounting said tool for movementacross the peripheral face of said regulating wheel in a path spacedabout the regulating Wheel axis substantially 904 from the line of.contact of the work with said surface, means for moving said dressingtool across the wheel surface, and means supporting said mounting meansand constructed so that the angular relation between the path of travelof the dressing tool and the axis of the regulating wheel may be variedat v Will and made substantially equal to the angular relation betweenthe axis of the regulating wheel and the path of travel of the work sothat the regulating wheel surface is concaved but presents asubstantially straight line of contact tol the work.

2. An apparatus for truing the peripheral operative surface of theregulating Wheel of a centerless grinding machine in which there existsanVV inclination between the axis of rotation of the regulating wheeland the path of travel of the work piece being ground so thatA theregulating wheel exerts a feeding component upon. the work,

including, in combination, a dressing tool, a carriage, means mountingsaid dressing tool in said carriage adapted to permit adjustment of saiddressing tool toward or away from the surface of said wheel, guidingmeans Vfor causing said carriage to move in a straight line and to carrysaid dressing tool across the face of said wheel, said guiding meansbeing positioned so that the path of travel of the dressing-tool isspaced about the periphery of the regulating wheel substantially fromthe line of contact of the work with the regulating wheel surface, andmeans for adjusting said guiding means so that the angular relationbetween the path of travel of the dressing tool and the axis oftheregulating wheel may bevsubstantially equal to the angular relationbetween the axis of the work and the axis of the regulating wheel.

3. An apparatus for truing the regulating wheel of a centerless grindingmachine having a grinding wheel positioned above the regulating wheel,the regulating wheel being pivotally mounted upon a support therebeneathfor adjustment of its axis into angular relation with respect to theaxis of the work and having mounted thereabout a water pan, comprisingin combination, a plate, means mounting said plate upon the Water panfor angular achustment about an axis transversely of the wheel axis, aslide mounted on said plate, a dressing tool carried by said slide, andmeans for moving said slide to carry said tool across the wheel surface,a forming bar vmounted upon said plate and adjustable inpositionthereon, and means on said slide for cooperating with said forming barto control the distance radially of said tool from the axis of saidwheel during movementI of said tool.

4. An apparatus for truing the operative' sur- 105 face of theperipheral regulating wheel of a; centerless grinding machine in whichthe regulating wheel is adjustably mounted so that the angle between itsaxis and the axis of the work piece being operated upon may be changedat will to vary the rate of feeding movement of the work, comprising, incombination, a dressing tool,

a carriage for supporting said dressing tool, guiding means for saidcarriage to guide said carriage in a substantially straight line and ina direction cross wise of the face of said regulating wheel, saidguiding means being positioned so that said dressing tool on thecarriage operates upon the peripheral surface of the regulating wheel ata point spaced substantially 90 from 120 the line of contact of the workwith the regulating wheel, means adjustably supporting said guidingmeans so that the latter and the carriage may be vgiven the same angularadjustment as is given to the regulating wheel, and means forcompensating for the effect of said adjustment and including means foradjusting said guiding means to cause the path offtravel of the dressingtool to make substantially the Vsame angle with the axis of theregulating wheel 's as the latter makes with the axis of the work.

